Wenglorz - Dipl. Ing. Helmut Wenglorz GmbH

Isolationsüberwachung in IT Netzwerken: Definitionen, Anwendungen, Merkmale

Electrical Network Configurations IT - System (ungeerdet, IT=isolé terre), TN - System (geerdet, TN=terre neutre), TT - System (geerdet, TT=terre terre)
IT - System Definition Ungrounded electrical low voltage systems for 2AC + 3AC or DC networks; description > VDE DIN 0100-410
all conductive parts are grounded that do not belong to the operating circuit.


IT-system provides the most advantages over the other network types in conjunction with insulation monitoring regarding the security of supply



Application in production plants and operating equipment , which can occur with abrupt interruptions significant economic damage and a further production must be avoided.

  • Chemical industry
  • Hard coal, brown coal and salt mining
  • Glass industry
  • Iron and steel industry
  • Concrete industry
  • Locomotives in rail transport
  • Power supplies on ships


Application in medically used rooms in services to patients where unplanned power interruptions can mean danger for life for patients.
  • Hospitals, f.e. operating rooms, intensive care units
Insulation Moniroting Application
  • Monitoring during operating only in IT-systems
  • Maximum protection for porple and equipment and against fire
  • Equipment availability is increased
  • Reduction of the risk of default to a minimum
  • Further operating is possible in the first insukation fault; these single-pole errors happen with a probability of 90 %; initiated. operating processes can be completed.
  • Continous monitoring has the advantage that troubleshooting can be initiated before the alrm message.
ISO-Wächter Function
  • The ISO monitor monitors the insulation resistance in the IT network during operating continously and activates a signal if the
  • Application of only one ISO monitor is permiited in a lectrically connected network.
  • Monitoring of disconnected areas is possible in grounded IT networks.


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